The invention relates to a driver assistance system for assisting the driver of a motor vehicle during a change of lane. The system includes a side area monitoring device and a lane directional stability monitoring device.
A driver assistance system of the above-described type is known, for example, from German Patent document DE 103 18 741 A1. Furthermore, a plurality of so-called lane changing assistants are known, which warn the driver by way of a side area monitoring device in the event of danger caused by passing vehicles or by vehicles in the blind spot range of the driver. A plurality of so-called lane directional stability monitoring devices (also frequently called “heading control” or “lane departure warning”), which recognize the vehicle's own traffic lane and which warn the driver and/or have a counter-steering effect in the event of a driving-out of the defined lane (for example, veering from one's own traffic lane). With respect to the technical background, reference is, for example, also made to the following patent literature: European Patent document EP 0 640 903 B1, German Patent document DE 197 02 383 A1 and German Patent document DE 102 26 481A.
It is an object of the invention to improve a driver assistance system having a side area monitoring device.
According to the invention, a driver assistance system is provided for assisting the driver of a motor vehicle during a change of lane. The system includes a side area monitoring device and a lane directional stability monitoring device. The side area monitoring device determines the degree of danger for a lane change and, in the event of a high degree of danger, independently of the degree of probability of the deliberateness of leaving the lane, causes a first driver-aid reaction at least in the form of a counter-steering, which is controlled by a connection between the side area monitoring device and the lane directional stability monitoring device, in the sense of steering back into the defined traffic lane or maintaining the directional stability within a lane. Advantageous further developments of the invention are described and claimed herein.
The driver assistance system for supporting the driver of a motor vehicle when leaving a defined lane is equipped with a side area monitoring device and with a lane directional stability monitoring device. The side area monitoring device is further developed such that it determines the degree of danger (for example, in two stages: dangerous/not dangerous; or in three stages: low/medium/high danger) for a lane change. In the event of a high degree of danger (for example, dangerous in the case of two stages; high danger in the case of three stages), a first driver-aid reaction occurs at least in the form of a counter-steering, which is controlled by a coupling between the side area monitoring device and the lane directional stability monitoring device with respect to lane maintenance. This takes place independently of the deliberateness with which the driver leaves the defined lane, particularly when leaving his own traffic lane.
The degree of danger is, for example, considered to be high when the side area monitoring device detects a fast-approaching vehicle in the passing lane. The degree of danger is, for example, considered to be low when the side area monitoring device detects a free or open passing lane.
In the case of a rather low degree of danger (for example, not dangerous, in a two-stage system; low or medium danger, in a three-stage system) determined by the side area monitoring device, the device preferably determines a degree of probability (for example, in a two stage system: likely intentional, likely unintentional; or in a three stage system: intentional, likely intentional, likely unintentional) with respect to the deliberateness of leaving the lane. In this case, the driver's likely intention is detected, for example, based upon his vehicle handling.
In the case of a low degree of probability (likely unintentional), a second driver-aid reaction is triggered.
As required, in the case of a high degree of probability (intentional or likely intentional), a second driver-aid reaction can be triggered, which influences the driver less than the second reaction in the case of a low degree of probability of the deliberateness of leaving the lane. Here, the second reaction in the case of a rather low degree of probability of the deliberateness of leaving the lane may be identical to the first reaction, and the second reaction in the case of a somewhat higher degree of probability of the deliberateness of leaving the lane may be no reaction. The first reaction preferably is a warning and a strong counter-steering. In a graduated manner, as a function of the degree or probability of the deliberateness of leaving the lane, the second reaction may, for example, be a warning and a slight counter-steering in a first stage; only a warning in a second stage; and no reaction in a third stage. A strong and slight counter-steering is defined, for example, by the respective pressure force required for overcoming the counter-steering reaction.
The degree of probability of the deliberateness of leaving the lane is assumed to be high, for example, when the turn signal is on. As an alternative or in addition, the degree of probability of the deliberateness of leaving the lane can be assumed to be rather higher when the speed at which the defined lane is being left is higher than a defined threshold and/or when the vehicle is accelerated. As an alternative or in addition, the degree of probability of the deliberateness of leaving the lane can also be assumed to be rather high when the distance to the vehicle driving ahead is considerably reduced.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.